The present invention refers to an electromechanical transducer for converting mechanical analog angular information to electrical linear information.
In servo and measuring technique, there is often a need for electrocmechanical transducers for converting mechanical analog data to electrical data. These data apply especially to angular information, for which the most common member is the potentiometer. The most common potentiometer generates an ouput voltage which is linear with respect to the mechanical rotation. A disadvantage of the potentiometer is that a movable galvanic contact slides along a resistance coil operating as a voltage divider. It is difficult to obtain high reliability and resolution and the accuracy will, therefore, be decreased.
Another electromechanical member is the rotatable inducer. There are many types of inducers, one of which, comprising a normal primary winding and a secondary winding, arranged mechanically in order to obtain a linear output voltage at the rotation of the rotor.
The most common type, providing the simplest winding technique, gives a trigonometrical output characteristic, according to the rotation, and is proportional to produce a sine and/or cosine signal.
In some precision-made embodiments, however, the device is provided with a so-called control winding in order to obtain a proportional factor of high accuracy. This is achieved by using a feed-back loop in order to obtain a constant ratio of secondary to primary turns. However, the first-mentioned linear types having a simple winding technique cannot be provided with such control windings.